Near-field investigations of the Landers earthquake sequence, April to July 1992
K. Sieh, L. Jones, E. Hauksson, K. Hudnut, D. Eberhart-Phillips, T. Heaton, S. Hough, K. Hutton, H. Kanamori, A. Lilje, Scott Lindvall, S.F. McGill, J. Mori, C. Rubin, J.A. Spotila, J. Stock, H.K. Thio, J. Treiman, B. Wernicke, J. Zachariasen
1993, Science (260) 171-176
The Landers earthquake, which had a moment magnitude (Mw) of 7.3, was the largest earthquake to strike the contiguous United States in 40 years. This earthquake resulted from the rupture of five major and many minor right-lateral faults near the southern end of the eastern California shear zone, just north...
Small fields in the National Oil and Gas Assessment
David H. Root, Emil Attanasi
1993, American Association of Petroleum Geologists Bulletin (77) 485-490
In the 1989 National Oil and Gas Assessment prepared by the U.S. Geological Survey (USGS) and the Minerals Management Service, undiscovered oil and gas resources in small fields were assessed separately from resources in fields containing more than 1 million bbl of oil equivalent. This paper concerns the USGS Part...
Chlorine-36 in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory; origin and implications
T.M. Beasley, L.D. Cecil, P. Sharma, P.W. Kubik, Udo Fehn, L. J. Mann, H.E. Gove
1993, Groundwater (31) 302-310
Between 1952 and 1984, low-level radioactive waste was introduced directly into the Snake River Plain aquifer at the Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho. These wastes were generated, principally, at the nuclear fuel reprocessing facility on the site. Our measurements of 36C1 in monitoring and production well waters,...
Nature of migrabitumen and their relation to regional thermal maturity, Ouachita Mountains, Oklahoma
Brian J. Cardott, Tim E. Ruble, Neil H. Suneson
1993, Energy Sources (15) 239-267
Two grahamite and three impsonite localities are within an 82-km-long segment of the Ouachita Mountains of southeastern Oklahoma. Grab samples were collected to study the petrographic and geochemical characteristics of the migrabitumen at the grahamite-impsonite transition and the relation of the migrabitumen to the regional thermal maturity pattern.Maximum and random...
Fire history of southeastern Glacier National Park: Missouri River Drainage
Stephen W. Barrett
1993, Report
In 1982, Glacier National Park (GNP) initiated long-term studies to document the fire history of all forested lands in the 410,000 ha. park. To date, studies have been conducted for GNP west of the Continental Divide (Barrett et al. 1991), roughly half of the total park area. These...
Fluvial response to late Quaternary climatic fluctuations, central Kobuk Valley, northwestern Alaska
G.M. Ashley, T. D. Hamilton
1993, Journal of Sedimentary Research (63) 814-827
Much of northwestern Alaska remained unglaciated during the Pleistocene and thus offers a favorable setting for examining long-term records of high-latitude geological and biological change. Epiguruk, a large cut bank 3.5 km long and up to 36 m high on the Kobuk River south of the Brooks Range in eastern...
Internal structure of the Sierra Nevada batholith based on specific gravity and gravity measurements
H.W. Oliver, Bryan Moore, R. F. Sikora
1993, Geophysical Research Letters (20) 2179-2182
About 6,000 specific‐gravity (SG) measurements of samples collected from nearly 200 granitic plutons comprising the central Sierra Nevada batholith yield a SG contour map across the batholith from 36.25° to 38° north latitude. With notable exceptions, SG decreases from values generally greater than 2.7 in the west to less than...
Geochemistry of surface sediments of Minnesota lakes
Walter E. Dean, Eville Gorham, Dalway J. Swaine
1993, GSA Special Papers (276) 115-133
Analyses of 36 trace, minor, and major elements were used to classify the sediments of 46 Minnesota lakes. Q-mode factor analyses grouped Minnesota lake sediments according to clastic-, carbonate-, organic-, and redox-related elements. Carbonate lakes occur in west-central Minnesota; their sediments have relatively high concentrations of CaCO3, Ba, and Sr....
Holocene climatic and limnologic history of the north-central United States as recorded in the varved sediments of Elk Lake, Minnesota: A synthesis
J. Platt Bradbury, Walter E. Dean, R.Y. Anderson
1993, GSA Special Papers (276) 309-328
Integration of the results and interpretations of geochemical, paleoecological, and sedimentological analyses of a varved sediment record provides a detailed chronicle of limnological and climatic changes for the past 10 ka at Elk Lake, west-central Minnesota. The early Holocene record at Elk Lake was controlled by circumstances of glacial history...
Environment of deposition of CaCO3 in Elk Lake, Minnesota
Walter E. Dean, R.O. Megard
1993, GSA Special Papers (276) 97-113
Elk Lake is near the present forest-prairie border in northwestern Minnesota, and is also located on the boundary between hard-water lakes that are typical of once-glaciated parts of the north-central United States and more saline prairie lakes of western Minnesota and the Dakotas. The sediments of the prairie lakes just...
40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia
Mark G. Steltenpohl, Michael J. Kunk
1993, GSA Bulletin (105) 819-833
40Ar/39Ar age spectra of hornblende, muscovite, and microcline, and total fusion ages of biotite from metamorphic rocks of the Inner Piedmont, Pine Mountain, and Uchee belts are reported. Mineral cooling ages from the eastern part of the Inner Piedmont are as follows: hornblende, 320 Ma; muscovite, 296 Ma; biotite, 293...
Extension and contraction within an evolving divergent strike-slip fault complex: The San Andreas and San Jacinto fault zones at their convergence in southern California
Douglas M. Morton, Jonathan C. Matti
Robert E. Powell, R.J. Weldon II, editor(s)
1993, Book chapter, The San Andreas Fault system: Displacement, palinspastic reconstruction, and geologic evolution
A variety of extensional and contractional structures is produced by strike slip faulting. The variety and extent of the structures are directly related to the kind and extent of geometric complexities of the fault zone or system. The area of convergence of the San Andreas fault zone and the much...
Landfill mapping using multi-disciplinary geophysical techniques at the U.S. Air Force Academy, Colorado Springs, CO
Robert Horton, John W. Busby, Michael H. Powers, Ronald N. Knoshaug
1993, Book, Proceedings of the symposium on the application of geophysics to engineering and environmental problems: SAGEEP '93
This paper describes a multi-disciplinary geophysical survey conducted over a landfill on the U.S. Air Force Academy grounds near Colorado Springs, Colorado. The landfill is known to contain waste generated during the construction of the Academy and reportedly contains buried steel drums. The purpose of the geophysical surveys was to determine the subsurface distribution...
Temporal and spatial variation in habitat characteristics of Tilefish (Lopholatilus Chamaeleonticeps) off the east coast of Florida
Kenneth W. Able, Churchill B. Grimes, Robert Jones, David C. Twichell
1993, Bulletin of Marine Science (53) 1013-1026
The tilefish, Lopholatilus chamaeleonticeps, constructs burrows in carbonate sediments off the central east coast of Florida at similar temperatures (8.6-15.4°C) and in similar sediment textures (high proportion of silts and clays) to conspecifics in the Mid-Atlantic Bight. The depths at which we observed tile fish off Florida (150-290 m), based...
The Pajarito Plateau: A bibliography
Frances Joan Mathien, Charlie R. Steen, Craig D. Allen
1993, NPS Southwest Cultural Resources Center Professional Paper 49
This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid...
A speculative history of the San Andreas fault in the central Transverse Ranges, California
R.J. Weldon II, K. E. Meisling, J. Alexander
Robert E. Powell, Jonathan C. Matti, editor(s)
1993, Book chapter, The San Andreas Fault system: Displacement, palinspastic reconstruction, and geologic evolution
It is generally accepted that the San Andreas fault formed between 4 and 5 Ma and that rocks west of it are now part of the Pacific plate, moving northwest relative to North America at 5 to 6 cm/yr. This model is inconsistent with the geologic record in the central...
Chapter 6: Chronology of displacement on the San Andreas fault in central California: Evidence from reversed positions of exotic rock bodies near Parkfield, California
John D. Sims
Robert E. Powell, R.J. Weldon II, Jonathan C. Matti, editor(s)
1993, Book chapter, The San Andreas Fault system: Displacement, palinspastic reconstruction, and geologic evolution
This chapter presents a synthesis of data pertaining to post-early Miocene slip on the San Andreas fault in central California and suggests a three-phase evolition of the San Andreas system. The cricial evidence that supports the three phases of evolution conies from the reversed positions of two exotic rock fragments...
The Klamath Falls, Oregon, earthquakes on September 20, 1993
S.R. Brantley
1993, Earthquakes & Volcanoes (USGS) (24) 104-146
The strongest earthquake to strike Oregon in more than 50 yrs struck the southern part of the State on September 20, 1993. These shocks, a magnitude 5.9 earthquake at 8:28pm and a magnitude 6.0 earthquake at 10:45pm, were the opening salvo in a swarm of earthquakes that continued for more...
Patterns of orographic uplift in the Sierra Nevada and their relationship to upper-level atmospheric circulation
Edward Aguado, Daniel R. Cayan, Brian D. Reece, Larry Riddle
1993, Conference Paper, Proceedings of the ninth annual pacific climate (PACLIM) workshop
We examine monthly and seasonal patterns of precipitation across various elevations of the eastern Central Valley of California and the Sierra Nevada. A measure of the strength of the orographic effect called the “precipitation ratio” is calculated, and we separate months into four groups based on being wet or dry...
Landslides caused by the Klamath Falls, Oregon, earthquakes of September 20, 1993
D. K. Keefer, R. L. Schuster
1993, Earthquakes & Volcanoes (USGS) (24) 140-146
The Klamath Falls earthquakes caused landslides throughout an area of about 420 sq km and as far as about 29 km from the epicenter, a distribution that is typical for magnitude 6 earthquakes (see graphs on following pages). Most of the landslides were rock falls or shallow, highly disrupted rock...
Significant bed elevation changes related to Gulf Stream dynamics on the South Carolina continental shelf
G. Gelfenbaum, M. Noble
1993, Continental Shelf Research (13) 385-405
Photographs of the seabed taken from an instrumented bottom tripod located approximately 100 km east of Charleston, South Carolina, reveal bed elevation changes of over 20 cm between July and November 1978. The tripod was in 85 m of water and was equipped with two current meters at 38.7 and...
Natural gas hydrates of the Prudhoe Bay and Kuparuk River area, North Slope, Alaska
Timothy S. Collett
1993, American Association of Petroleum Geologists Bulletin (77) 793-812
Gas hydrates are crystalline substances composed of water and gas, mainly methane, in which a solid-water lattice accommodates gas molecules in a cage-like structure, or clathrate. These substances commonly have been regarded as a potential unconventional source of natural gas because of their enormous gas-storage capacity. Significant quantities of naturally...
Earthquakes, May-June 1993
W. J. Person
1993, Earthquakes & Volcanoes (USGS) (24) 147-152
A major earthquake (7.0≤M<8.0) occurred on June 8 during this reporting period. This magnitude 7.3 earthquake was centered off the east coast of Kamchatka. there were no earthquake-related deaths during the months of May and June. Seismicity in the United States included two strong earthquakes in Alaska. The first, a magntidue...
Seasonal use of conservation reserve program lands by white-tailed deer in east-central South Dakota
Jeffrey H. Gould, Kurt J. Jenkins
1993, Wildlife Society Bulletin (21) 250-255
The Conservation Reserve Program (CRP_, a provision of the 1985 Food Security Act, subsidizes landowners to take highly erodible lands out of cultivation and seed them to perennial cover for 10years. In eastern South Dakota, 0.5 million ha were enrolled in the CRP from 1985 to 1990 (Agric. Stabilization and...
Paleogeographic implications of molluscan assemblages in the Upper Cretaceous (Campanian) Pigeon Point Formation, California
William P. Elder, LouElla Saul
1993, Book chapter, Mesozoic paleogeography of the Western United States
The Pigeon Point Formation crops out along the San Mateo County coastline in a northern and southern sequence of folded and faulted strata. Correlation of the two sequences remains somewhat equivocal, although on the basis of biostratigraphy and a reversed magnetic interval both appear to have been deposited during the...
